Soil column experiments were conducted to evaluate the effect of different rates of sulphur application on gypsum formation in calcareous soils. Elemental sulphur was applied to three soils at the rate of 0.5%, 1.5% and 3.0%. Soils columns were incubated at 30C for 3, 6, 9 and 18 weeks and were intermittently leached with distilled water. Thin soil sections were microscopically examined to detect and evaluate gypsum formation in soils. Chemical analysis of gypsum was also used for the same purpose. Gypsum, as anisotropic anhedral aggregates, was noticed with thin sections in all sulphur treated soils. Formation of gypsum was confined to the uppermost 10 cm and was optically recorded after 9 and 18 weeks of incubation treatments for two of the Soils of AI-Qassecm and Derab at all periods of incubation for the AI-Kharj sandy soil. These findings were in agreement with the chemical data which showed the same trend. The second level of sulphur (1.5%) application is highly recommended as most of it can be oxidized after (9-18 weeks).